You feel your bowels churn, another pile of soft shit about to force its way out into the diaper. You claw at the cotton waistband, hoping to remove it, but it won't budge, the lining quickly becoming skin tight. You try to hold it in but the pressure from this next wave of shit is far too great, filling the brief, now on tight enough so it just holds in the rapidly increasing torrent against your body with no more leakage.
Panicking, you rush to the front counter, hoping the old clerk can Help. "SIR!!! You gotta help me, I put on this diaper and-"
"Ah," he interjects, "I see you picked from our anthro line, good choice. He smiles at you as you release a loud, wet fart, expelling more shit from your asshole. "You'll get used to that as you start changing."
"CHANGING?!?!?" you shout, "I WANT THIS THING OFF!!!" Tears rolling down your face.
"I'm sorry sir, that product was intended for the more...kinky, furry crowd." He says. "It can't come off, It wouldn't be a good product if it just slid off ass you filled it with shit, now would it?" The old man says, patting you on the head. "Don't worry, you'll get used to it, and afterwards it'll open up so you can drain or consume it, play with yourself, whichever you perfer." You start feeling strange and fall to the floor. "Don't worry, I promise you'll love your new form," the old man whispers in your ear.